1. Field of the Invention
The invention relates in general to lamp harps and, more particularly, embodiments of the present invention relate to lamp harps wherein an inverted U-shaped bracket-headed machine screw assembly is mounted to the top of the harp frame for rotation through a limited arc so as to prevent a lamp shade from contacting a bulb mounted in an associated lamp socket.
2. Description of the Prior Art
Lamp harps have been well known for many years. Many lamp harps provide for the mounting of a lamp shade that is mounted through an assembly to the harp frame at the top of the harp. See, for example, Auerbach U.S. Pat. No. 1,946,959 (an upwardly extending threaded stud is fixed to the top of the harp so the angle of the shade is not adjustable); Berger U.S. Pat. No. 2,435,954 (an inverted U-shaped bracket-threaded stud assembly is rotatably mounted to a straight portion of the harp frame at the top of the frame so that the lamp shade can be tilted through whatever arc can be traversed until the shade encounters an obstacle—such as a light bulb—that prevents further rotation); and Schwartz et al. U.S. Pat. No. 2,481,355 (similar to Berger U.S. Pat. No. 2,435,954 showing an inverted U-shaped bracket-headed machine screw assembly). The uncontrolled rotation of the shade mounting assemblies of, for example, Berger and Schwartz et al. presents a fire safety hazard. When a combustible shade comes into contact with or close proximity to a hot bulb there is a risk of fire. Various elaborate rotational mechanisms had been previously proposed without addressing the fire safety issue. See, for example, Fanshier U.S. Pat. No. 3,309,515 (an elaborate and expensive machined clamp that is activated by a threaded lock purports to clamp the shade in a particular position); Truax et al. U.S. Pat. No. 3,281,590 (the shade is mounted through an elaborate and expensive ball-socket assembly); and Benander U.S. Pat. No. 2,670,432 (a multi-part shade mounting that apparently permits rotation around two perpendicular axes). Various complicated and expensive expedients had been previously proposed for limiting the rotation of a shade. See, for example, Jacobson U.S. Pat. No. 4,414,618 (an elaborate and expensive leveling plate mounted on top of a conventional inverted U-shaped bracket-threaded stud assembly); and Goldfine U.S. Pat. No. 3,016,455 (an elaborate and expensive lockable frusto-spherical bearing mounted on top of a conventional inverted U-shaped bracket-threaded stud assembly). Many other proposed expedients had been offered. Chilo U.S. Pat. No. 2,264,145, for example, discloses an expedient wherein the bulb is mounted in a downwardly depending configuration and the shade pivots with the bulb. The prior art devices and methods are not without their shortcomings. A major shortcoming of typical prior art devices and methods is that they are either too complicated and expensive to make or they present a fire hazard. Those concerned with these problems recognize the need for improvements.
These and other difficulties of the prior art have been overcome according to the present invention.